Add dev commands: is-installed, shell (for debugging package status)

src/StaticPHP/Command/Dev/ShellCommand.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace StaticPHP\Command\Dev;
+
+use StaticPHP\Command\BaseCommand;
+use StaticPHP\Runtime\SystemTarget;
+use StaticPHP\Util\GlobalEnvManager;
+use Symfony\Component\Console\Attribute\AsCommand;
+
+#[AsCommand('dev:shell')]
+class ShellCommand extends BaseCommand
+{
+    public function handle(): int
+    {
+        // need to init global env first
+        GlobalEnvManager::afterInit();
+
+        $this->output->writeln("Entering interactive shell. Type 'exit' to leave.");
+
+        if (SystemTarget::isUnix()) {
+            passthru('PS1=\'[StaticPHP] > \' /bin/bash', $code);
+            return $code;
+        }
+        if (SystemTarget::getTargetOS() === 'Windows') {
+            passthru('cmd.exe', $code);
+            return $code;
+        }
+        $this->output->writeln('<error>Unsupported OS for shell command.</error>');
+        return static::FAILURE;
+    }
+}